Patents by Inventor Kazuo Takaragi

Kazuo Takaragi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7770009
    Abstract: According to the invention, techniques for authenticating that a digitally signed document is genuine. Specific embodiments according to the present invention can determine whether a digital signature was generated by a digital signature generator, or if the digital signature was generated by a third party posing as the digital signature generator. Specific embodiments can provide independent verification of digital signer identity based upon prior signed messages, time/date stamps, and the like. Techniques according to the present invention can be embodied in methods, apparatus, computer software and systems.
    Type: Grant
    Filed: December 4, 2007
    Date of Patent: August 3, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Kunihiko Miyazaki, Ryoichi Sasaki, Kazuo Takaragi, Seiichi Susaki, Toshiyuki Moritsu, Mizuhiro Sakai, Mitsuru Iwamura, Tsutomu Matsumoto
  • Patent number: 7711714
    Abstract: A method and a device for managing a computer network, especially a technique for ensuring the security of a network. A computer network system in which computers are connected to each other through transmission lines, each computer stores the data which constitutes a moving type software exclusively used for security and transmitted together with a message when the computer transmits the message to another computer of the system, and executes the moving type software by using the stored data upon receiving a message from another computer.
    Type: Grant
    Filed: September 1, 2006
    Date of Patent: May 4, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Kazuo Takaragi, Seiichi Domyo, Hiroshi Yoshiura
  • Patent number: 7694126
    Abstract: According to the present invention, techniques, including a method and system, for restoring and/or validating data and/or associated signature log entries are provided. One embodiment of the present invention provides a method for validating a restored message, having an entry generated in a signature log for a message, where the entry includes cryptographic information associated with the message. Next, when said message is lost, the restored message is generated responsive to a request; and the restored message is validated using the signature log. In another embodiment a method for validating a selected log entry by using a signature log having a plurality of recorded log entries is provided. The method includes: computing a cryptographic value for the selected log entry; and determining if the cryptographic value is part of another recorded log entry.
    Type: Grant
    Filed: August 8, 2005
    Date of Patent: April 6, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Kunihiko Miyazaki, Hiroshi Yoshiura, Seiichi Susaki, Ryoichi Sasaki, Kazuo Takaragi, Hisashi Toyoshima, Takeshi Matsuki
  • Patent number: 7549208
    Abstract: In a method of mounting a planar electronic circuit chip onto a flexible sheet together with another planar electronic element, the electronic circuit part and the another electric element are selected so that the planar surface of the another electric element is greater than the planar surface of the electronic circuit chip, and the another electric element and the electronic circuit chip are mounted on the sheet so that the planar surface of the another electric element and the planar surface of the electronic circuit chip are in parallel with the sheet surface, and the planer surface of the electronic circuit chip is accommodated within the planar surface of the another electric element as viewed in a direction perpendicular to the sheet surface.
    Type: Grant
    Filed: October 20, 2003
    Date of Patent: June 23, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Chikashi Okamoto, Kazuo Takaragi, Kazutaka Tsuji, Mitsuo Usami, Chizuko Yasunobu, Asahiko Sobe, Yasuhiro Tsunemi, Hiroyuki Yagi
  • Patent number: 7447339
    Abstract: A unique code generating apparatus for generating, according to biometric information representing a physical or behavioral feature of a user, a unique code as a unique value for the biometric information includes a statistic information generating section for conducting statistical analysis for a feature of biometric information for registration and generating statistic information, a statistic information table generating section for summarizing the statistic information for each biometric information, setting a unique code for each statistic information, and generating a statistic information table unique to the biometric information, a unique code extracting section for applying to the statistic information table the statistic information generated by the statistic information generating section according to biometric information for collation and extracting an associated unique code from the table, and an output processing section for outputting the unique code extracted by the unique code extracting sec
    Type: Grant
    Filed: October 15, 2004
    Date of Patent: November 4, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Masahiro Mimura, Kenta Takahashi, Kazuo Takaragi, Masakatsu Nishigaki, Yoichi Shibata
  • Publication number: 20080098232
    Abstract: According to the invention, techniques for authenticating that a digitally signed document is genuine. Specific embodiments according to the present invention can determine whether a digital signature was generated by a digital signature generator, or if the digital signature was generated by a third party posing as the digital signature generator. Specific embodiments can provide independent verification of digital signer identity based upon prior signed messages, time/date stamps, and the like. Techniques according to the present invention can be embodied in methods, apparatus, computer software and systems.
    Type: Application
    Filed: December 4, 2007
    Publication date: April 24, 2008
    Applicant: Hitachi, Ltd.
    Inventors: Kunihiko Miyazaki, Ryoichi Sasaki, Kazuo Takaragi, Seiichi Susaki, Toshiyuki Moritsu, Mizuhiro Sakai, Mitsuru Iwamura, Tsutomu Matsumoto
  • Patent number: 7359515
    Abstract: A symmetric-key cryptographic technique capable of realizing both high-speed cryptographic processing having a high degree of parallelism, and alteration detection. The invention includes dividing plaintext composed of redundancy data and a message to generate plaintext blocks each having a predetermined length; generating a random number sequence based on a secret key, generating a random number block corresponding to one of the plaintext blocks from the random number sequence, outputting a feedback value obtained as a result of operation on the one plaintext block and the random number block, the feedback value being fed back for using the operation on another plaintext block, and performing an encryption operation using the one plaintext block, random number block, and feedback value.
    Type: Grant
    Filed: November 21, 2006
    Date of Patent: April 15, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Soichi Furuya, Kazuo Takaragi, Hiroyuki Kurumatani, Masashi Takahashi, Kunihiko Miyazaki, Hisayoshi Sato, Dai Watanabe
  • Publication number: 20080054427
    Abstract: A non-contact identification semiconductor device is provided with a semiconductor chip including a receiving circuit that receives an inquiry to the non-contact identification semiconductor device, a memory that stores identification information of multiple bits and a sending circuit that sends the identification information. An antenna coupled to said semiconductor chip receives the identification information from said semiconductor chip and transmits the identification information outside of said non-contact semiconductor. The long side length of the semiconductor chip is not greater than 0.5 mm in plane dimension, and the identification information is stored by a pattern printed by an electron beam.
    Type: Application
    Filed: October 23, 2007
    Publication date: March 6, 2008
    Inventors: Mitsuo USAMI, Kazutaka Tsuji, Takeshi Saito, Akira Sato, Kenji Sameshima, Kazuo Takaragi, Chizuko Yasunobu
  • Patent number: 7333972
    Abstract: The technology includes the steps of: associating material-object identification code identifying each individual material object with material-object information representing information about material object identified by identification code and storing identification code and material-object information in material-object information database in each of business categories; sending code and information stored in database in each business category; integrating items of information having same code with each other among codes and items of information received from database in each business category to generate integrated material-object information, associating identification code with integrated material-object information identified by code and storing identification code and integrated material-object information in integrated database; requesting to send integrated material-object information associated with given identification code; reading requested integrated material-object information from integrat
    Type: Grant
    Filed: July 11, 2005
    Date of Patent: February 19, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Chikashi Okamoto, Kazuo Takaragi, Yasuko Fukuzawa, Hideki Tokuyama, Mitsuo Usami
  • Patent number: 7330949
    Abstract: A method is adopted in a control apparatus for controlling ID information stored in a storage medium in conjunction with a terminal for reading the ID information from the storage medium and used to catalog information for the storage medium into a memory employed in the control apparatus. In an operation to catalog information into the memory of the control apparatus, the terminal receives the information, reads the ID information from the storage medium and transmits the information and the ID information to the control apparatus and the control apparatus catalogs the information and the ID information in the memory by associating the information with the ID information.
    Type: Grant
    Filed: June 30, 2006
    Date of Patent: February 12, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Kazuo Takaragi, Chikashi Okamoto
  • Patent number: 7309019
    Abstract: A method of checking a sheet as to forgery thereof, the sheet being provided with an electronic circuit chip from or in which information can be read out or written and having visible information. The method includes a step of encrypting the visible information of the sheet and storing the encrypted visible information in the electronic circuit chip, and a step of determining discriminatively the authenticity of the sheet by comparing the visible information of the sheet with the information stored in the electronic circuit chip.
    Type: Grant
    Filed: January 4, 2006
    Date of Patent: December 18, 2007
    Assignees: Hitachi, Ltd., Hitachi Research Institute
    Inventors: Chikashi Okamoto, Kazuo Takaragi, Kazutaka Tsuji, Mitsuo Usami, Chizuko Yasunobu, Asahiko Isobe, Yasuhiro Tsunemi, Hiroyuki Yagi
  • Patent number: 7305558
    Abstract: According to the invention, techniques for authenticating that a digitally signed document is genuine. Specific embodiments according to the present invention can determine whether a digital signature was generated by a digital signature generator, or if the digital signature was generated by a third party posing as the digital signature generator. Specific embodiments can provide independent verification of digital signer identity based upon prior signed messages, time/date stamps, and the like. Techniques according to the present invention can be embodied in methods, apparatus, computer software and systems.
    Type: Grant
    Filed: October 19, 2000
    Date of Patent: December 4, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Kunihiko Miyazaki, Ryoichi Sasaki, Kazuo Takaragi, Seiichi Susaki, Toshiyuki Moritsu, Mizuhiro Sakai, Mitsuru Iwamura, Tsutomu Matsumoto
  • Patent number: 7298029
    Abstract: A non-contact identification semiconductor device is provided with a semiconductor chip including a receiving circuit that receives an inquiry to the non-contact identification semiconductor device, a memory that stores identification information of multiple bits and a sending circuit that sends the identification information. An antenna coupled to said semiconductor chip receives the identification information from said semiconductor chip and transmits the identification information outside of said non-contact semiconductor. The long side length of the semiconductor chip is not greater than 0.5 mm in plane dimension, and the identification information is stored by a pattern printed by an electron beam.
    Type: Grant
    Filed: April 8, 2005
    Date of Patent: November 20, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Mitsuo Usami, Kazutaka Tsuji, Takeshi Saito, Akira Sato, Kenji Sameshima, Kazuo Takaragi, Chizuko Yasunobu
  • Patent number: 7280659
    Abstract: In a buffer and a state included in a pseudorandom number generating apparatus, the state has the configuration of assuming that the unit length of data processing is n, the state has a size of 3×n bits, and the buffer has a capacity of 32×n bits, and according to clock control, a state transformation section (state transformation function) for conducting a state alteration from time t to time t+1 uses a nonlinear function F (having an n-bit input and an n-bit output) twice, or two different nonlinear functions F and G respectively once. The state transformation section has such a configuration that a nonlinear function such as a round function of a block cipher sufficiently evaluated as to the cryptographic security and implementation.
    Type: Grant
    Filed: April 18, 2002
    Date of Patent: October 9, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Dai Watanabe, Soichi Furuya, Kazuo Takaragi
  • Patent number: 7224796
    Abstract: In a buffer and a state included in a pseudorandom number generating apparatus, the state has the configuration of assuming that the unit length of data processing is n, the state has a size of 3×n bits, and the buffer has a capacity of 32×n bits, and according to clock control, a state transformation section (state transformation function) for conducting a state alteration from time t to time t+1 uses a nonlinear function F (having an n-bit input and an n-bit output) twice, or two different nonlinear functions F and G respectively once. The state transformation section has such a configuration that a nonlinear function such as a round function of a block cipher sufficiently evaluated as to the cryptographic security and implementation.
    Type: Grant
    Filed: January 16, 2002
    Date of Patent: May 29, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Dai Watanabe, Soichi Furuya, Kazuo Takaragi
  • Patent number: 7210043
    Abstract: Techniques of improving the safety of an information processing system at low cost are provided, the information processing system having an OS provided with an access control function based upon discretionary access control for preventing illegal accesses to files. A method and apparatus for providing the information processing system with functions and areas usable only by a specific user different from a system administrator. The areas are provided with an access control function in order to prevent the access control function from being tampered.
    Type: Grant
    Filed: February 20, 2002
    Date of Patent: April 24, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Kunihiko Miyazaki, Shinji Itoh, Hiroshi Yoshiura, Kazuo Takaragi, Masato Arai, Toshiaki Arai, Takeshi Matsuki, Hisashi Toyoshima
  • Patent number: 7200232
    Abstract: A symmetric-key cryptographic technique capable of realizing both high-speed cryptographic processing having a high degree of parallelism, and alteration detection. The invention includes dividing plaintext composed of redundancy data and a message to generate plaintext blocks each having a predetermined length, generating a random number sequence based on a secret key, generating a random number block corresponding to one of the plaintext blocks from the random number sequence, outputting a feedback value obtained as a result of operation on the one plaintext block and the random number block, the feedback value being fed back for using in the operation on another plaintext block, and performing an encryption operation using the one plaintext block, random number block, and feedback value.
    Type: Grant
    Filed: March 28, 2001
    Date of Patent: April 3, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Soichi Furuya, Kazuo Takaragi, Hiroyuki Kurumatani, Masashi Takahashi, Kunihiko Miyazaki, Hisayoshi Sato, Dai Watanabe
  • Patent number: 7200682
    Abstract: A time stamp generating system has a time distribution server for generating time data depending on time and a user PC for holding time certification objective digital data. The time distribution server generates time data corresponding to a time point and distributes the time data. The user PC calculates time stamp generating data by using the time certification objective data as an input, acquires the time data generated by the time distribution server, and processes the time data on the basis of the time stamp generating data to obtain a time stamp.
    Type: Grant
    Filed: August 20, 2002
    Date of Patent: April 3, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Kunihiko Miyazaki, Seiichi Susaki, Kazuo Takaragi, Hiroshi Yoshiura, Takeshi Matsuki, Hisashi Toyoshima, Mitsuru Iwamura, Tsutomu Matsumoto, Ryoichi Sasaki
  • Publication number: 20070064944
    Abstract: A symmetric-key cryptographic technique capable of realizing both high-speed cryptographic processing having a high degree of parallelism, and alteration detection. The invention includes dividing plaintext composed of redundancy data and a message to generate plaintext blocks each having a predetermined length; generating a random number sequence based on a secret key, generating a random number block corresponding to one of the plaintext blocks from the random number sequence, outputting a feedback value obtained as a result of operation on the one plaintext block and the random number block, the feedback value being fed back for using the operation on another plaintext block, and performing an encryption operation using the one plaintext block, random number block, and feedback value.
    Type: Application
    Filed: November 21, 2006
    Publication date: March 22, 2007
    Inventors: Soichi Furuya, Kazuo Takaragi, Hiroyuki Kurumatani, Masashi Takahashi, Kunihiko Miyazaki, Hisayoshi Sato, Dai Watanabe
  • Patent number: 7178026
    Abstract: An identification code management method and management system includes that the issue and distribution of an ID code having a message authentication code are managed thereby to efficiently and reliably manage a material object using the ID code. An electronic circuit chip with an ID code having a message authentication code stored in a read-only area is used as an identification tag. The information at an ID code order receiving terminal and an identification tag production factory terminal are consolidated and collectively managed at an ID code management terminal. Thereby, the ID code management terminal is inquired of highly confidential information or requested to process the information as required so that an ID code utilization terminal is not required to store the same information.
    Type: Grant
    Filed: July 12, 2005
    Date of Patent: February 13, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Chikashi Okamoto, Kazuo Takaragi, Yasuko Fukuzawa